Currently both the milling machines that comprise a single fastened head, with a work table arranged in a horizontal plane being the one that moves, as well as milling machines that comprise a single head, in this case moving, with the horizontally-arranged work table being the one which is kept fastened, are very well known. In both cases there is a limited machining capacity given that for parts of large dimensions a single head requires an extensive machining period. In the case in which it is the work table that is moved, it is not possible to previously palletise the workpiece and therefore take full advantage of the capacity of the machine. Another inconvenience is that the load moved along the work table is variable depending on the weight of the workpiece, and if this weight is high, it negatively affects the dynamics in the machining.
There are also known milling machines with work tables arranged in a horizontal plane which comprise more than one head, but the problem of said machines reside in the heavy structure which is necessary to be enable the heads to move on five axes, which makes said machines unsuitable to produce complex geometric parts, such as aeronautical parts, with high velocities and accelerations in order to achieve high productivity. On the other hand, the heads of said machines keep the distance between them fixed, with the machining by panoplies not being possible, with the consequent waste of material and the increase of the production cost.
These configurations therefore carry a high number of unproductive movements, bringing an undesired increase in the manufacturing time and an inefficient use of the raw material. These circumstances translate into cost increase of the machining process, and therefore a cost increase of the final product.
On the other hand there are disadvantages that the horizontal arrangement of the work surface brings. One of them is the high occupied space which it entails and another is the difficult disposal of waste linked to the machining process. The fact of reducing the occupied floor space may entail not needing to expand the factory facilities so as to be able to house all of the machinery, as well as a greater ease and efficiency in the movements of all of the resources which are to be found in a factory. On the other hand, machining the workpieces on a horizontal surface makes the disposal of the waste truly difficult, involving consumption of additional resources, or in other words, making the machining process more expensive.
Nowadays, the market demands a high degree of flexibility and efficiency, and the use of each and every one of the resources is of great importance. For this reason the present invention presents a milling machine that has a great production capacity with more efficient machining on five axes. Particularly for parts with complicated geometry, obtaining very few contouring errors, given that they comprise at least three heads with mutually independent mobility, a robust and light moving structure, whilst saving floor space and greatly easing the disposal of waste due to the vertical arrangement of the machine.